Construction sector membrane

ABSTRACT

The invention relates to a construction sector membrane ( 1 ) with at least one outer fibrous nonwoven web layer ( 2 ) constructed to produce a bond with an applied material such as mortar, concrete or an adhesive. To achieve good adhesion of the membrane ( 1 ) in concrete, mortar or an adhesive, the invention provides that the fibrous nonwoven web layer ( 2 ) is at least regionally hydrophilic

TECHNICAL FIELD OF THE INVENTION

This invention relates to a construction sector membrane having at least one outer fibrous nonwoven web layer constructed to produce a bond with an applied material such as mortar, concrete or an adhesive.

BRIEF DISCUSSION OF RELATED ART

Membranes with fibrous nonwoven web layers for use in the construction sector are already known. Such membranes are used for example for forming a bond to certain built-in components or sealing membranes via mortar or concrete. The outer fibrous nonwoven web layer serves to improve adhesion, since for example mortar or concrete would easily detach from an unlaminated smooth surface.

However, mortar or concrete has been observed to fail to penetrate deeply enough into the fibrous nonwoven web layer of known membranes and therefore insufficient fibers become embedded. This leads to problems in the case of substrates which sag or undergo length changes. In the case of tiling, for instance, insufficient adhesive pull strength leads to detachment from springy undersurfaces.

Some attempts are made in practice to solve the aforementioned problem by applying a very great deal of mortar to the membrane as it is being laid, or by pressing the membrane with its fibrous nonwoven web layer very deep into a relatively thick/deep layer of mortar in order that improved embedding of the mortar into the fibers of the fibrous nonwoven web layer may be achieved.

BRIEF SUMMARY OF THE INVENTION

The invention provides a membrane of the type in question that avoids the aforementioned disadvantages.

This is achieved by invention when the fibrous nonwoven web layer in the aforementioned construction sector membrane with outer fibrous nonwoven web layer is at least regionally hydrophilic. We have determined that, surprisingly, the attachment of mortar, concrete or else adhesive, in particular dispersion or other adhesives comprising hydraulic binders, is distinctly increased when the fibrous nonwoven web layer is at least regionally hydrophilicized. Hydrophilicization evidently leads to an appreciably improved detachment of the fibers of the fibrous nonwoven web layer because, for example when mortar and concrete are used, the make-up water penetrates with the hydraulic binder into the fibrous nonwoven web layer very deeply and therefore the fibrous nonwoven web fibers acquire a distinctly increased binding into the mortar or concrete. Depending on the identity and extent of hydrophilicization, we found an in some instances appreciably enhanced adhesive pull strength on concrete, mortar and adhesives compared with nonhydrophilicized fibrous nonwoven web layers. Adhesive pull strength was found to be increased by more than 20%, in some instances by more than 50%. It is incidentally a further advantage of the present invention that only a comparatively small amount of concrete, mortar or adhesive is required to achieve sufficient adhesive pull strength. Lastly, the membrane does not need to be pressed particularly deeply into the mortar bed, or the mortar pressed onto the fibrous nonwoven web layer, to achieve adequate penetration. The present invention ultimately makes it possible to save concrete, mortar or adhesive.

It has also been determined in connection with the present invention that specifically the use of synthetic fibers, in particular polyolefins and in particular polypropylene fibers as fiber material of the fibrous nonwoven web and the hydrophilicization thereof leads to a particularly good result. True, other materials of construction from which a bonding layer bridge web could be produced are also conceivable in principle. However, they must always be ruled out when large amounts of the fibrous nonwoven web layer are needed and the respective fiber materials are very costly. It is particularly through the use of polyolefins and particularly polypropylene that it is possible to produce very economical membranes which, moreover, are even in the hydrophilicized state stable to contact with water, for example, and do not tend to hydrolyze.

We have further determined that the fibrous nonwoven web layer need only be hydrophilic over part of its layer thickness to achieve adequate adhesive pull strength. Advantageously, the outer, near-surface region of the fibrous nonwoven web layer should be made hydrophilic, while the surface-remote region of the fibrous nonwoven web layer is made nonhydrophilic. We have determined that it is sufficient for between 20 and 80%, preferably between 40 and 60% of the layer thickness to be hydrophilicized to achieve good adhesive pull strength.

Because the hydrophilicization of the fibrous nonwoven web layer only has to be partial across the layer thickness, starting from the outer, near-surface region of the fibrous nonwoven web layer, the production costs of the membrane of the present invention are only minimally increased compared with a fibrous nonwoven web layer which has not been rendered hydrophilic, as it is not the entire fibrous nonwoven web layer which is hydrophilicized.

Alternatively or else additionally to the regional hydrophilicization across the layer thickness, the fibrous nonwoven web layer is only hydrophilic over part of its surface. This can be achieved for example by making only some of the fibers of the fibrous nonwoven web layer hydrophilic and leaving some others nonhydrophilicized. It is also possible to hydrophilicize the fibers as such only partially. It is also possible for certain surface regions to have been rendered hydrophilic while other regions have not been rendered hydrophilic. This is another context where we have determined that a hydrophilicization between 20 and 80% of the total surface of the membrane, preferably between 40 and 60% is sufficient to achieve good adhesive pull strength values.

We have further determined that increased adhesive pull strength results irrespective of how the hydrophilicization of the individual fibers of the fibrous nonwoven web layer was carried out. The first option is for the fibers of the fibrous nonwoven web layer to be hydrophilicized in the course of fiber production by addition of at least one hydrophilicizing additive. It is also possible for the fibers of the fibrous nonwoven web layer or the fibrous nonwoven web layer itself to be hydrophilicized during or after production by outer application of at least one hydrophilicizing agent. For example, an outer application of spin finish or else soap solution is possible. Lastly, hydrophilicization of the fibers of the fibrous nonwoven web layer or else of the fibrous nonwoven web layer as a whole is possible by any chemical and/or physical treatment. Similarly, pretreatments of the fibrous nonwoven web layer or of the fibers are possible for example by a corona or plasma pretreatment.

Depending on the application sector, the membrane of the present invention may comprise at least one further layer. The membrane may have two or else more layers and comprise one or else two fibrous nonwoven web layers rendered hydrophilic according to the present invention. Embodiments are possible, for example, wherein the membrane has two outer or external hydrophilicized fibrous nonwoven web layers between which is disposed at least one further membrane having a certain function, for example a sealing or decoupling function.

We have determined that the membrane of the present invention is preferably useful as sealing membrane, decoupling membrane or as a drainage membrane. A further field of use for the membrane of the present invention is in the use as flashing or waterstop tape between distinct regions which are to be treated with render, for example the transition from the wall to the ceiling. Such tapes or strips can also perform the function of sealing, physical separation and movement equalization.

A further use is in constructing the membrane as wall covering or panel heating.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention as well as the prior art will now be described with reference to the drawing, where

FIG. 1 shows a schematic cross-sectional view of a known membrane to which an adhesive mortar has been applied,

FIG. 2 shows a schematic cross-sectional view of the membrane of FIG. 1 to which a tile has been applied,

FIG. 3 shows a schematic cross-sectional view of a present invention membrane to which adhesive mortar and a tile have been applied, and

FIG. 4 shows a schematic cross-sectional view of a fibrous nonwoven web layer of a present invention membrane.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows part of a known membrane a. The membrane a comprises a fibrous nonwoven web layer b, the outer surface of which has had an adhesive mortar c applied to it with a notched trowel (not depicted). The adhesive mortar c has penetrated into the upper zone of the fibrous nonwoven web layer b under the pressure of the trowel teeth.

When later the tile d is pressed into the mortar bed, the adhesive mortar will ideally become distributed evenly under the tile d and will at the same time be pressed uniformly into the upper zone of fibrous nonwoven web b. Attachment is mechanical as a result of the fibers of the fibrous nonwoven web layer b lying in the adhesive mortar c, which undergoes curing/hardening. This state is depicted in FIG. 2, in which tile d is present on the layer with the adhesive mortar c. It can be seen that the adhesive mortar c has merely penetrated into the surface region of the fibrous nonwoven web layer b.

FIG. 3, then, depicts the embodiment according to the present invention. A membrane 1 is shown for use in the construction sector, although membrane 1 can in principle comprise any underlayment membrane to which something else still has to be applied on the outside, or else a wall covering or panel heating which is adhered to the subsurface. The membrane 1 comprises an outer fibrous nonwoven web layer 2 composed of synthetic fibers, namely polyolefins. In the present case, the fibrous nonwoven web layer 2 is composed of polypropylene, since polypropylene is inexpensive and is stable for the planned area of use in particular. The fibrous nonwoven web layer 2 is made up of a multiplicity of fibers 3. The outside surface 4 of the fibrous nonwoven web layer 2 has had applied to it, in a layer, an adhesive mortar 5 to which a tile 6 has been applied in turn.

In contrast to the embodiment described in FIGS. 1 and 2, the embodiment as per FIG. 3 provides that the fibrous nonwoven web layer 2 is at least regionally hydrophilic. The hydrophilicization at least of the outer region of the fibrous nonwoven web layer 2 causes some of the adhesive mortar 5 to penetrate more deeply into the fibrous nonwoven web layer 2. As an effect of the hydrophilicization, the make-up water of the adhesive mortar 5 penetrates distinctly deeper with adhesive mortar particles into the fibrous nonwoven web layer 2 compared with the embodiment, which represents the prior art, shown in FIG. 2, resulting in an appreciably increased binding in of the fibers 3. The depicted embodiment has a more than 100% increased penetration depth for the adhesive mortar 5 compared with the prior art as per FIG. 2. This results in an appreciably increased adhesive pull strength compared with the bonding bridge web of FIG. 2.

FIG. 4 depicts an embodiment in which fibrous nonwoven web layer 2 has two layer regions 7, 8 to make up the layer thickness. The outer layer region 7 is hydrophilicized, while the other layer region 8 has not been rendered hydrophilic. Lastly, the membrane 1 depicted in FIG. 4 is made up of two individual fibrous nonwoven web layers 2, which are joined together.

What is not depicted is the fact that the membrane is only partly hydrophilicized because only a certain proportion of the fibers 3 are hydrophilicized, while the other portion has not been rendered hydrophilic. 

1.-15. (canceled)
 16. A construction sector membrane comprising at least one outer fibrous non-woven web layer constructed to produce a bond with an applied material, wherein the fibrous nonwoven web layer is at least regionally hydrophilic.
 17. The construction sector membrane according to claim 16, wherein the fibrous nonwoven web layer comprises synthetic fibers of polyolefins.
 18. The construction sector membrane according to claim 16, wherein the membrane is configured for use with concrete, mortar or adhesive.
 19. The construction sector membrane according to claim 16, wherein the fibrous nonwoven web layer is only hydrophilic over part of its layer thickness.
 20. The construction sector membrane according to claim 16, wherein merely an outer, near-surface region of the fibrous nonwoven web layer is hydrophilic.
 21. The construction sector membrane according to claim 16, wherein 20 to 80% of the layer thickness is hydrophilic.
 22. The construction sector membrane according to claim 16, wherein the fibrous nonwoven web layer is only hydrophilic over part of its surface.
 23. The construction sector membrane according to claim 16, wherein only some fibers of the fibrous nonwoven web layer are hydrophilic.
 24. The construction sector membrane according to claim 16, wherein between 20 and 80% of the surface of the fibrous nonwoven web layer is hydrophilic.
 25. The construction sector membrane according to claim 16, wherein fibers of the fibrous nonwoven web layer are hydrophilicized in the course of fiber production by addition of at least one hydrophilicizing additive.
 26. The construction sector membrane according to claim 16, wherein fibers of the fibrous nonwoven web layer or the fibrous nonwoven web layer are hydrophilicized during or after production by outer application of at least one hydrophilicizing agent.
 27. The construction sector membrane according to claim 16, wherein fibers of the fibrous nonwoven web layer or the fibrous nonwoven web layer are hydrophilicized by chemical and/or physical treatment.
 28. The construction sector membrane according to claim 16, wherein the membrane comprises at least one further layer.
 29. The construction sector membrane according to claim 16, wherein the membrane is constructed as a sealing membrane, as a decoupling membrane, as a drainage membrane or as flashing or waterstop tape.
 30. The construction sector membrane according to claim 16, wherein the membrane is constructed as wall covering or as panel heating.
 31. The construction sector membrane according to claim 17, wherein the synthetic fibers comprise polypropylene.
 32. The construction sector membrane according to claim 18, wherein the adhesive comprises dispersion or other adhesives comprising hydraulic binders.
 33. The construction sector membrane according to claim 20, wherein 40 to 60% of the layer thickness is hydrophilic.
 34. The construction sector membrane according to claim 24, wherein between 40 and 60% of the surface of the fibrous nonwoven web layer is hydrophilic. 